The invention relates to substrate polishing techniques, including chemical mechanical polishing (CMP).
Chemical mechanical polishing is a process by which a substrate surface is smoothed (planarized) to a uniform level by a polishing pad and an abrasive slurry. A substrate to be polished is usually mounted on a rotatable carrier head and pressed against a moving polishing pad. The polishing pad typically includes an abrasive surface. An abrasive chemical solution (slurry) may be introduced onto the polishing pad to assist in the polishing process. Typically, a rinse arm supplies rinse fluid (e.g., de-ionized water) to the polishing pad to remove coagulated slurry and other material from the polishing pad surface.